set mission to night, spawn a red chemlight, and separately a red chemlight and a 40mm smoke grenade. fly by at a moderate, or slow speed in helicopter.
To test, create a marker named "ChemTest", create a flying helicopter, this init code:
_pos = getMarkerPos "ChemTest";
_cx = _pos select 0;
_cy = _pos select 1;
_cz = _pos select 2;
_nil = "Chemlight_red" createVehicle _pos;
_nil = "G_40mm_Smoke" createVehicle _pos;
_nil = "Chemlight_red" createVehicle [_cx + 10,_cy + 10,_cz];